Re: [PATCH mptcp-next v4 6/6] selftests: mptcp: userspace pm remove id 0 address

[Geliang Tang <geliang.tang@suse.com>]

On Fri, Aug 18, 2023 at 11:34:00AM +0200, Matthieu Baerts wrote:
> Hi Geliang,
> 
> On 18/08/2023 09:12, Geliang Tang wrote:
> > This patch adds a selftest for userpsace PM to remove id 0 address.
> > 
> > A new helper userspace_pm_rm_id_0_address_ns2() is added, in it use
> > 
> >         ./pm_nl_ctl rem token $tk id 0
> > 
> > to remove id 0 address.
> > 
> > Signed-off-by: Geliang Tang <geliang.tang@suse.com>
> > ---
> >  .../testing/selftests/net/mptcp/mptcp_join.sh | 29 +++++++++++++++++++
> >  1 file changed, 29 insertions(+)
> > 
> > diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh
> > index 322adac0cb1b..1c5c0bbae38f 100755
> > --- a/tools/testing/selftests/net/mptcp/mptcp_join.sh
> > +++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh
> > @@ -3336,6 +3336,14 @@ userspace_pm_rm_id_0_subflow_ns2()
> >  	wait_rm_sf $ns2 1
> >  }
> >  
> > +userspace_pm_rm_id_0_address_ns2()
> > +{
> > +	local tk=$(evts_get_info token "$evts_ns2")
> > +
> > +	ip netns exec $ns2 ./pm_nl_ctl rem token $tk id 0
> > +	wait_rm_addr $ns2 1
> > +}
> > +
> >  # $1: subflows in ns1 ; $2: subflows in ns2
> >  chk_subflows()
> >  {
> > @@ -3514,6 +3522,27 @@ userspace_tests()
> >  		kill_events_pids
> >  		wait $tests_pid
> >  	fi
> > +
> > +	# userspace pm remove id 0 address
> > +	if reset_with_events "userspace pm remove id 0 address" &&
> > +	   continue_if mptcp_lib_has_file '/proc/sys/net/mptcp/pm_type'; then
> > +		set_userspace_pm $ns2
> > +		pm_nl_set_limits $ns1 0 1
> > +		speed=10 \
> > +			run_tests $ns1 $ns2 10.0.1.1 &
> > +		local tests_pid=$!
> > +		wait_mpj $ns2
> > +		userspace_pm_add_sf 10.0.3.2 20
> > +		chk_join_nr 1 1 1
> > +		chk_mptcp_info subflows 1 subflows 1
> > +		chk_subflows 2 2
> > +		userspace_pm_rm_id_0_address_ns2
> > +		chk_rm_nr 1 0
> > +		chk_mptcp_info subflows 1 subflows 1
> > +		chk_subflows 1 1
> 
> When we only send a REMOVE_ADDR, why do we have one subflow that is
> being removed? Is it because the other peer disconnected the subflow
> linked to ID=0?

Yes. And remove id 0 subflow test got this "chk_subflows 1 1" too.

When closing the initial subflow in __mptcp_close_ssk(), dispose_it is
false, then tcp_disconnect is invoked. This will send a MP_RST to close
a subflow on the peer too. So chk_subflows after closing the initial
subflow is '1 1', not '2 1'.

In v5, chk_rst_nr() is added in these tests.

Thanks,
-Geliang

> 
> Do you mind checking this please?
> Because the remove address command should not result in a host sending
> both a REMOVE_ADDR and a FIN. That's up to the other host to take an
> action when the REMOVE_ADDR is received, no?
> 
> Cheers,
> Matt
> 
> > +		kill_events_pids
> > +		wait $tests_pid
> > +	fi
> >  }
> >  
> >  endpoint_tests()
> 
> -- 
> Tessares | Belgium | Hybrid Access Solutions
> www.tessares.net